Systems, known as fire alarm systems, which monitor regions such as buildings to sense the presence of fire conditions are often installed in commercial buildings, residences and the like. Such systems usually incorporate a common control element, a fire alarm panel, which is coupled via cables or via RF to a plurality of ambient condition detectors. The ambient condition detectors can include fire, smoke and gas detectors all without limitation.
Detectors of the type noted above generally are not intended to sense and indicate to the fire alarm control unit the presence of conditions which favor backdrafts. Backdrafts can occur in circumstances where the oxygen in a room has been depleted due to a fire, but the fuel and smoke remain at a high temperature.
When first responders, such as firefighters, respond to a fire alarm and encounter a closed room where the oxygen has been depleted, opening a door or a window into the room can feed the fire therein with additional oxygen. This can in turn produce a sudden, very extensive burst of flame as fire produced gases heat and expand due to the inflowing oxygen) which can erupt from the opening and envelop the firefighters causing death or serious personal injury.
There thus is an ongoing need to be able to determine, prior to attempting to open or enter closed rooms, whether the conditions are present to support a backdraft. Preferably such detectors could be readily installed in the same regions or buildings with other ambient condition detectors and fire monitoring systems and coupled thereto. It would also be desirable if such detectors could be configured so as to be installable at a distance from the closed room or region which is to be monitored for the backdraft condition.